


The Skeletons Will Play

by foxymonstrocity



Category: Undertale (Video Game)
Genre: F/M, In The Dog House pt 2, Love, NSFW, Polyamory, Smut, Underfell, magic dicks, skeletons in heat, snuggles
Language: English
Status: In-Progress
Published: 2018-08-16
Updated: 2018-10-16
Packaged: 2019-06-28 05:19:19
Rating: Mature
Warnings: Creator Chose Not To Use Archive Warnings, No Archive Warnings Apply
Chapters: 2
Words: 4,911
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/15700578
Author URL: https://archiveofourown.org/users/foxymonstrocity/pseuds/foxymonstrocity
Summary: The aftermath of In The Dog House!When the dogs away, the skeletons will play!It’s THAT a time of year and neither of the skeletons have had a mate for this before. None of you are really sure how to handle it. It’s awkward and sexy and definitely entertaining.





	1. The “Season” Begins

**Author's Note:**

> this will probably be about 3 chapters long, it was super fun to write and now i will hideaway heheh
> 
> enjoy you naughty little muffins !
> 
> (requests for oneshots are open)

Papyrus demanded you move in immediately, what with you being mates and the incident regarding your black eye. Though, as nice as it sounded, you had to decline. It was much too soon. You had no doubts in your mind that the skeletons were your soulmates but you weren’t ready to fling yourself into something you weren’t prepared for. However that didn’t stop you from spending almost every night at their house. Every spare moment of their time was dedicated to you. One night you’d fall asleep in Sans room, after his brother made him clean it entirely, curled up next to him. Another you’d be in Papyrus’ room, enveloped in his surprisingly cuddly, spooning position. Or you would help yourself to the couch and wake up with both skeletons tangled with your limbs. Despite the amazing sleepovers, you promised Papyrus you would take up the offer soon, maybe after a couple of dates!

“Dates are not necessary, you belong to us! Y-You belong with us.” Papyrus said softly, silently respecting your decision.

“Hm. How should we even do dates?” You pondered out loud.

“I just said they’re not necessary!” Papyrus crossed his arms.

“A date sounds fun, I can take ya to Grillby’s.” Sans said from the kitchen.

“That is not a proper date, Sans!” Papyrus exclaimed as if his brother offered to take you to the dump.

“Thought ya weren’t on board with dates.” You teased, sitting on the arm of the couch.

Papyrus grumbled something to himself which made you laugh. You gave each skeleton a kiss on the cheekbone and said a goodbye, you were off to work. They both stood up, wary to let you go alone but you assured them you would be fine. Ever since the skeletons marked you, you’ve had a relatively peaceful time. No one bothered you or even glanced your way. It probably had to do with the glowing bite marks on your shoulders, which they bestowed upon you the very night they expressed their feelings. You were a blushing mess afterwards.  
Now that you thought about it, was it weird neither of them have tried anything on you? Monsters were big on consent but even before that, neither brought up the offer or suggested foreplay. It didn’t bother you one bit, maybe the skeletons weren’t interested in sex. You weren’t even positive if they had genitals but if memory serves you right, Sans had two porn magazines under his mattress. One thought led to another and you perked up, realizing what day it was. You blushed in embarrassment, your heat cycle would be starting soon. This was the first time you would have a mate for it! Your face flushed darker with (soul color). Would Sans and Papyrus be willing to help you- or even stay away from you?

You would need to visit a shop immediately.

Conveniently, you worked right next to a shop that sold what you needed. You could grab it after work. You worked at a gardening company, mainly you dug holes for them because a dog was quicker than a shovel. You were about to enter the shop when you saw the big sign on the door. Closed. Closed?! Your boss called you last night, how could- Then it dawned on you. The only fathomable explanation; you weren’t the only one starting your heat cycle.  
Normally females started first and the aroma triggered male monsters to begin theirs. Jealousy, overly aggressive behavior or possessive all showing traits of a monster in heat. You’d just contradicted yourself by saying monsters were big on consent, as much as they were the only catch was this. Even with marks, heat cycles brought out the worst in all monsters. Female monsters would be bitchy, horny, snappy and extremely irritable. Most un marked females stayed indoors at this time, for their own safety or other’s was up for debate. You usually stayed in your home because you almost bit off a monsters hand, you were so annoyed. Male monsters were just as bad but 100% more aggressive, dominant and assertive. Some male monsters preferred avoiding their heat altogether and would distance themselves until it was safe to go back, otherwise you’d stay indoors and deal with the under-stimulation.  
Your eyes glanced towards the shop you needed to go to, begging for it to be open. It was! You hurried inside and desperately searched for the pill. Monsters could get pregnant anytime as long as it was wanted, however this pill assured a safe heat cycle. There were even medicines in practice for trying to subside the feeling altogether but for now this will do. When you couldn’t find it, you rushed over to the counter and asked about it.

“Sorry, sweetie, we sold out for today.” The monster said, genuinely apologetic.

“B-B-But!” Part of you wanted to panic. The, normally, laid back dog was about to freak out. This would be your first cycle with a mate. Whether or not they wanted to engage in any activity was fine but you always took the pill just so be safe.

“Relax.” The monster tried to calm you, “We will be getting more tomorrow. Want me to set a box aside for you?”

“Y-Yes, please, thank you!” You sighed, relaxing once again. You pulled some gold out of your pocket and paid in advance for the tiny box that would save your butt.

“Just bring this back so we know it’s your order.” The monster smiled at you.

You took the paper and began to make your way home. Guess you should stop by the skeleton house hold to make sure they know you’re safe. The walk home was cold and silent, aside from the howling wind and snow crunching under your paws. Is this something you should mention to the skeletons? They were now your soulmates, after all, how awkward could it be!

“She couldn’t open her shop because she’s in heat!?” Papyrus was blushing at the explanation you gave him. 

Yeah, You should’ve known it would’ve been very awkward. 

“Y-Yeah, it is that about that season?” You mumbled, earning a glance from Sans who was watching TV.

“W-Well!” Papyrus cleared his throat, “This opens an opportunity for the Great and Terrible Papyrus!”  
He darted towards the fridge and brought back 3 red flowers, “I-I wish to take you on a proper date.” 

You giggled and could hear Sans chuckling from his spot on the couch.

“No chortling allowed! No mentioning earlier, either!” Papyrus glared at the two of you.

Gingerly, you took the flowers and smiled, “Of course I’ll go on a date with you, Pap.”

“Of course you will!” Papyrus blushed, remaining in a proud pose.

“What’d ya have in mind?” You asked, batting your eyelashes at him.

“I-I have a plan. You need to go home at once to prepare for our date!” He yelled.

“Y’mean it’s tonight?”

“Of course! That’s what I said!” 

“Ok, Pap, what should I wear?”

“I do not care!” He paused in thought and blushed again, “Something nice...”

With that he rushed up the stairs, to the bathroom and slammed the door. You could hear the shower start to run when Sans started chuckling again. You made your way over to the couch and pounced at him, laying on top of him.

“Aye, get off!” He groaned.

“Why? Do I weigh a skele-ton?” You laughed at your own joke and Sans stared to blush. You moved off him so he could sit up properly but remained in his lap. 

“So why does Papyrus get to take me out first?” You asked.

Sans shrugged.

“Is it ‘cause you don’t wanna?” You pretend pouted.

“N-Nah! Y’know I do.” Sans pulled you closed to him, “Jus’ boss gets first pick.”

“Fair, I guess.” You stuck your tongue out.

“Ya should go get ready.” Sans squeezes your butt.

“I’ll send you pictures while I change.” You wink, placing a kiss on his forehead before you left.

“Please do.” Sans smirked, sniffing the air as you left.

Monsters each had their own distinct smell. For example, you told Sans he smelled of cherry syrup and pine- which shocked him and his brother, he thought for sure he wreaked of mustard. You also told Papyrus he smelled like cinnamon and smoke, to which he demanded you smell him as something more menacing but secretly liked this combination. To both the skeletons, you smelled of vanilla bean and honey. As you left, the aroma behind was strong. Sans held back a moan as he caught another whiff of your scent. His eye sockets widened when something began to rise in his shorts. You had given Sans a boner before but this felt different. He was overcome with the sensation to ravish you over and over- Stop! Sans realized his soul was aching for you and he ran to his room. He grabbed a shirt you’d worn two nights ago and inhaled its scent. He smiled and relaxed as it still smelled of you. Sans worry remained, they’d been around for your heat cycle before. The same scent lingered by your house, Papyrus was extremely curious what it was. As was Sans but when he heard you’d almost bitten someone’s hand off earlier that day, he was pretty certain what it was. He and Papyrus had to steer away from your house for a week before you were acting like yourself again.  
When the brothers heat cycle began first it was Papyrus who started, he- in a sense- was weaker than his brothers’ will and caved. Sans’ was triggered shortly after that and the two remained inside their house, in their own rooms, the rest of the week. After that they agreed that if one had started, the other would leave the house to remain vigilant. Sans didn’t mind his too bad, it wasn’t as intolerable for him as his brothers was. Probably because Sans was a huge pervert but, hey, it saved him some unbearable feelings. Speaking of the devil, Papyrus pounded on his brothers door and called out that he would be leaving. Sans said something along the lines of ‘whatever, have fun.’ but would definitely be tagging along.

You had on a high waisted, black, pencil skirt that complimented your figure. Your top was a white, strapless one with long sleeves, an open back and covered with little black stars. All your favorite shirts with long sleeves usually covered your hands, you enjoyed them that way. Papyrus would probably demand you wear shoes so you decided on a simple pair of black, small wedges. Your doorbell rang a few times, you let your hair down before you answer it. Of course it’s Papyrus, he’s wearing black slacks, a black, silk button up with a white tie. All complimented with his signature belt, covered in spikes and a skull in the center. He takes the view of you in and you return the favor. You both start to blush when you realize you’re staring at one another. Papyrus smiled and extends his hand to you, which you take and return the smile.

You weren’t entirely certain where he intended to take you, sometimes Papyrus could be mysterious. Other times he was extremely obvious but this was one of the scenarios where he’s being sneaky. He hushes you and tells you to stop guessing when you arrive in front of the MTT Resort. You stare at the building in front of you, it’s extremely tall! A little more than halfway up you can tell there’s a restaurant and assume that’s where you’re going. Papyrus leads you into the elevator and protectively wraps his arm around your shoulders, he’d prefer your waist but you’re too short. You felt really hot, not in a good way. Papyrus saw the discomfort on your face and decided to compliment you, hoping it’d help.

“You look beautiful, as always.” He kisses the top of your head, making you blush.

“Y-You look amazing too.” You fan yourself. He chuckles and the elevator door conveniently opens, as you suspected it’s a luxurious restaurant.

The moment Papyrus is seen, he’s greeted by a monster and lead to a table. You shyly follow him, ears flattening as you notice people watching you. Maybe you should’ve picked something that would cover these two markings. The first month of having a mark made, it’s incredibly vivid. Your shoulders were practically glowing red to every monster who dared look at you. Papyrus growled and you noticed the eyes drift away from you. His finger is brought under your chin, forcing you to look in his direction, “That is my mark, I think you have made a great decision to proudly display it.” 

His voice sent shivers up your spine. Papyrus was certainly acting different tonight! It definitely wasn’t helping the burning feeling in your soul that was begging for him and Sans. You pushed the sensation to the back of your mind and sat in the chair Papyrus pulled out for you. 

“This place is incredible.” You admit as Papyrus sits across from you.

“You truly enjoy it?” He asked, his proud smile widening. 

You nod, wagging your tail at his enjoyment. He noticed this and couldn’t help but allow his smile to remain.

“So, did your dating manual tell you to do this?” You joke, remembering Papyrus had a book about dating once.

Surprisingly, he laughed, “No, actually. This was Sans idea. He said that he had elsewhere to take you and that I should use his ‘backup’ place.”

Your ears perked at that, “Really? That lazybones planned something so well that he had a ‘backup’?!”

Papyrus shared a laugh with you at that. You certainly made these skeletons do crazy things. The two of you studied your menus and selected your desired courses and went back to talking. Papyrus was listening but it wasn’t hard to see something was bothering him. Just before your meal arrived a table was knocked over, two monsters growling at each other. Papyrus had been eyeing them all night, both out with their respective mates but still being hard headed. Your ears flagged as the scene began to unfold. Before anything too crazy happened, Papyrus reaches his arm out towards the two monsters. Immediately, they’re surrounded by dark red magic and hovering slightly above the ground.  
He got up and stalked towards them, setting the two monsters on the ground.

“You two will not ruin my date.” He commanded, the monsters shot each other a dirty look that made Papyrus growl lowly. He moved to roll up his sleeve when his own mark started glowing. The mere action made the monsters bow and shout apologies. Papyrus returned to you, still rolling up his sleeves. 

You blushed, “You don’t have to do that.”

“Do what?” He smirked, having never seen this shy side of you, he enjoyed it.

“Showing off my mark.” You chuckle, fiddling with the sleeves of your shirt. 

“I rather like it, my pet.” Papyrus admits, admiring the mark you gave him on his wrist- or where his wrist would be. 

The food came, along with more apologies regarding the fight Papyrus had to split up. Halfway through your meal you began to feel sick. Maybe sick was the wrong word but something felt wrong. You excused yourself to go to the bathroom, splashing some water on your face. It didn’t help. Your heart continued racing, you felt it was way too hot in here. It could be because you were in Hotlands but you felt it was something else. After all you started feeling this as soon as you were alone in the elevator with Papyrus.  
You didn’t want to ruin this evening, your mate was clearly trying very hard to have a nice date with you. You return to Papyrus, who was trying not to play with his food but knew it was rude to eat without your company.

“Sorry.” You said quickly, grabbing your water and sipping it.

“It is alright. Are you feeling sick, (Name)?” Papyrus asked, gently touching your cheek.

“M-Maybe you’re right, I might be gettin’ sick.” You said, debating whether you were nervous, in heat or actually sick. 

“Shall we return home, my pet?” He asked. You nodded quickly, his hand still on your cheek.

The journey of your walk home was uncomfortable and slow. You half jokingly suggested a race.

“It seems my wonderful ideas are rubbing off on you!” Papyrus laughed, “And you must be feeling better to challenge ME to a race!”

Oops. Guess you were doing this now.

Papyrus won, obviously, earning you a mini lecture of how you were lazy. You were too tired to argue with him. He was partially correct. Your interests involved lounging about and marking art pieces, the most active you got was from working! Papyrus gifted you with a kiss for your efforts. Your tail wagged as you kissed him back, pressing your body to his as you pushed him up against the door. That earned you a moan from the skeleton and you both jumped away at that.

“I’m sorry, Pap, I-I-” You were blushing furiously.

“Do not apologize, my pet.” Papyrus’ nickname for you was getting more and more becoming. 

“I should probably go home.” You swore you heard him whine at that. 

“I suppose you are right. I have made you quite flustered, have I not?” Papyrus smirked to himself.

“Oh hush.” You kissed him one more time and waved as you began to make your short walk home. Papyrus waved back to you and headed inside.

You opened the door to your house, not surprised to see it unlocked. What shocked you was Sans, eating cereal out of the box on your counter! 

“What the hell!”

“S’up?” He said, still stuffing his face.

“What’re you doing here?” You laughed, leaning up against the counter.

Sans blushed and swallowed the handful of cereal he’d just thrown in his mouth. 

“Uh, so, y’know how we was talkin’ ‘bout heats and shit, earlier?” Sans said.

“Yeah...?”

“Boss is in his, now. Think I could guess why.” Sans smirked, eyeing you up and down.

“YOU CAN TELL?!”

“Duh.” Another handful of cereal, “Boss’ never been good at seein’ the obvious.”

“Bu- That doesn’t explain why you’re here!” You were blushing but angrily pointing a finger at the skeleton.

“Less ya want both of us in heat, I gotta stay away from him. N’ protect you at the same time.” 

“I don’t need you to protect me.” 

“Sure. You keep tellin’ yourself that ‘till you get pounded into by-“

“Enough! Enough! You can sleep on the couch.”

“What?!” He whined, “Why can’t I sleep with you?”

“My room is the only one with a lock. What if I trigger.. Your.. Y’know!” You blushed.

“Didn’t realize hookin’ up with me sounded to bad to ya.” Sans wiggles his eyebrows. You fought back a laugh.

“It might,” He shrugged, “I’m pretty good at keepin’ it under control... Never had a mate for it, though.” He said honestly. 

This conversation wasn’t an awkward with Sans but it was still making you both quite flustered.

“I’m gonna shower and go to bed,” You kissed him, “Night, Sansy.” 

“Night, babe.” He smiled dreamily as you walked away. 

This was defiantly going to be a long night.


	2. The Night With Sans

**Notes for the Chapter:**

> so sorry this took so long!   
> i thought i lost this chapter and was going to start rewriting when i found it!!

The night was long indeed. 

After your shower you threw on a black, oversized, long sleeved shirt and tried to lie comfortably in bed. At first the bed was cold, which felt nice against your hot body, but as you absorbed the cool feeling it faded away. You were hoping to just sleep until the unbearable feeling between your legs went away. Your soul ached for Sans and Papyrus and you felt yourself get hotter, if that was possible. Rolling off the bed and onto your paws you got up and moved to the other side of your room. You cranked the AC up for the third time and even debated opening up a window. You glanced at the clock while you were standing up and realized only 3 hours had gone by.  
You threw yourself onto the floor and groaned. At least the carpet was cooler than your bed. As you remained on the floor, you turned your head to peak underneath your door. Through the crack you could barely see the other side of the hall to the bathroom. You whimpered a bit as you shuffled on the floor, laying on your back now. Maybe another shower would help cool you down? A single, soft knock at your door made you turn your head to it.

“Sans?” You asked the door. Don’t be dumb, who else would it be? 

“No, the boogie man.” His voice replied. You could practically see him smirking. 

“You ok?” He asked, sitting outside and leaning against the door. You crawled over to do the same, feeling a bit better just being closer to him.

“No. I’m hot.” You whined.

“Yeah you are.” Sans laughed.

“Shut up, you know what I mean.” You couldn’t help but smile. 

“Don’t ya have any’a those pills?” He asked, “Y’know, to help with that?”

Your ears perked up at that.

“Sans, would you do me a huge favor?”

“How huge?”

“Walk to the store in the middle of the night for me, huge.” The store would be open, you’re almost positive they never closed. 

Sans wanted to groan and ask why you couldn’t do it yourself but he answered his own question. Your scent was overwhelming, it was even testing Sans’ patience. It took every bone in his body not to teleport in there and-

The lock opened.

Hesitantly, Sans opened the door. The first thing he noticed was that you room was freezing cold! The second thing he noticed was you bent over your laundry hamper, digging through clothes. Your shirt was lifted up just enough so the skeleton see your perfectly round ass, your lips folded tight and practically begging for Sans to come taste you. Your pussy was dripping and the aroma of your honey was suddenly stronger than his will. Just as you found what you were looking for, you squeaked as you felt Sans grip the base of your tail and hold you in place. His hot, red tongue gave a long lick over your juices. Your legs quivered as you moaned his name, “Sa~ans~”

Sans had to stop. It’s not that he didn’t want to- because, fuck, did he want to! It’s just that he didn’t want your first time with him to be a lust-driven one. Believe it or not, Sans wanted to remember every loving moment as he cherished your body and left bite marks all over you. Some where along the lines of making love and making you scream.   
Yet between that, and the fact his tongue was literally slipping between the folds of your dripping pussy lips, he couldn’t stop. Just a taste was all he needed to get him thirsting for more. Sans couldn’t stop himself as he began to slide his hot, red tongue further inside you. You squeaked and stiffened as he slid up to your clit. Your legs shook more and you collapsed, falling to the floor on your hands and knees. Sans pulled away before your legs gave out and smirked at the scene unfolding before him. This couldn’t get anymore perfect.  
You let out another squeak of surprise as Sans mounted you from behind, dry humping you. Though the term was loose, nothing was dry, his shorts were definitely getting wet from your arousal. You swore you could feel something poking your pussy, practically begging to slip inside. So he did have a dick after all! But your mind was fuzzy, your train of thought came crashing down the moment Sans started to eat you out. Your arousal was building up, your own heat getting to you.

“Sans~” You said again, begging for his attention.

This only made him rut harder against you. His claws dug into your hip as he mindlessly humped you, his tongue hanging out of his mouth as he panted. Finally the skeleton slowed down, furiously grinding against you instead. You moaned at the sensation, his clothed dick rubbing against your pussy in the best way. Even in a lustful haze you could tell what he was trying to do, he was attempting to slide off his shorts while grinding against you. The thought made you even wetter than before which sent Sans over the edge. He could smell your arousal and it finally made him snap.   
In one careful motion, he roughly was able to rub his shorts and boxers off his hip bones. The skeleton managed to shrug off his jacket and shirt after, sliding his cock carefully between your folds. You whimpered at the teasing motion, silently begging him to hurry up and fuck you. Sans had just enough sense to be gentle at first, slowly sliding his cock inside you. You moaned as he did, arching your back. The heat around your body seemed to fade as he did this and your soul was filling with contentment, the ache for Sans was gone now that he was here.

“Oh, baby.” Sans groaned, trying to keep a slow pace.

“Sansy~” You moaned, all you could say was his name and it was turning him on so much! 

Sans would bite his lip if he could, his smile just grew as he began to rock into you. His cock stretched you in the best of ways as he popped your cherry. The moment of pain was over and now you needed him to be merciless.

“Fuck me, Sansy.” You whimpered.

That was all he needed to hear. 

Sans moaned loudly as he pushed his dick back inside your tight pussy. Stars, you were tight. It felt amazing on his cock. He couldn’t control himself as he began to hammer into your pussy, making you moan louder. His thrusts were desperate and hard, the immense pleasure was becoming too much too fast. His cock filled you up again and as he pounded into you, your first orgasm spilt over.   
You called out his name which only made him move faster. He was hugging you from behind, thrusting into you roughly. Sans tongue hung out of his mouth again as he began panting. He grunted your name a few times before he felt his end was nearing. You came twice more, moaning loudly as he continued to pound into you recklessly. Your walls were so tight around him you could feel his dick twitching inside you, letting you know he was about to cum. You managed to push yourself back to help him get deeper inside you, it worked, making you both moan.

“(Name). (Name). (Name)!” Sans growled your name as he rutted into you a few more times, pushing himself as deep as he could into your pussy as he came. You squeaked and tried to wiggled away but he pulled you back and bit down on your shoulder. You cried out his name as he made you bleed, the pleasure still intense. Sans unloaded himself into your pussy and even gave a few extra thrusts to make sure he was empty. You whimpered as he did, your entire body shaking. Sans hissed as he pulled his cock out but smirked as he watched his work. It was perverted, no doubt, but sexy in his mind to watch his red cum leaking out of your pussy. You moved to lie on your stomach, your legs failing you, but Sans held your legs up. He feeling himself get hard again as he made you keep all his cum inside of you.   
You panted hard, the agonizing heat between your legs dimmer than before but still annoying.

“S-Sans, you jerk.” You said after you finally caught your breath.

Sans snapped out of his perverted trance and began blushing. 

“Y-Ya could’ve just asked, I would’ve let ya.” You groaned as you turned around, sitting facing the embarrassed skeleton.

“I-I-I-“ Sans couldn’t stop stuttering. Or sweating. Were you genuinely upset? He couldn’t tell, but he wouldn’t blame you if you were. Sans just fucked you without permission!

You leaned forward and kissed his nervous, toothy smile. He relaxed a bit at that but was still quite embarrassed.

“Y-You ain’t mad?”

“How could a monster be upset after a lay like that?” You purred, crawling into his lap and straddling him.   
Sans was definitely hard now. His cock was right between your pussy lips, it took everything in him not to pound into you again.

“I’m pretty great at that, ain’t I?” He smirked, trying to play it cool. 

You snorted, pressing your forehead to his. 

“‘M sorry,” He mumbled, “That wasn’t exactly how I wanted it to go.”

“What do you mean?” You tilted your head, pulling back to look at the skeleton.

Sans blushed and avoided your eyes, “I kinda was hopin’ to make it more special.”

You bit your bottom lip as a blush arose to your cheeks. You acted as if you were shuffling positions and as you sat back in Sans lap comfortably, you slid his cock inside you. He gasped and clutched your hips tightly, claws digging past your fur and into your skin. You leaned forward and pressed another kiss on his lips, “By all means, make this round special.”


End file.
